In connection with this application, a fibre web of a non-woven fabric means a fibre web manufactured of some fibre, such as cotton, glass or stone wool fibre or some other fibre by means of a card. At the manufacture of a synthetic non-woven fabric, for example, the purpose of folding is to fold a desired number of web layers on each other to form a fabric of a desired thickness to be used in waddings of different textiles, for instance.
At conventional manufacture of non-woven fabrics, raw material is brought as bales to an opener, which breaks up the bales, after which the fibres are led to a licker-in dispersing the fibres to a mass as even as possible. After this the fibres are typically led to a feed box and from there to a card. These structures relating to the production of a non-woven fabric are stationary, and the fibre web is not brought until finished by means of belt or roller conveyors to a separate folding device, which can be of pendulum or sled type. Thus, to provide the folding, both a separate folder and separate means to transfer the fibre web to the folder are required, and on the other hand, the folder shall be the bigger, the longer is the folding breadth desired. In general, it can be stated that the folder increases the total costs of the apparatus and the need of space substantially.